Automatic slack control draft gear



April 12, 1955 c. sPRousE 2,706,050

AUTOMATIC sLAcK CONTROL DRAFTGEAR Filed Jan. 6, 1954 2 Sheets-Sheet 1 April 12, `955 Q SPRQUSE 2,706,050

AUTOMATIC SLACK CONTROL DRAFT GEAR Filed Jan. 6, 1954 2 Sheets-Sheet 2 United States Patent C AUTOMATIC SLACK CONTROL DRAFT GEAR Clifton Sprouse, Abbeville, S. C.

Application January 6, 1954, Serial No. 402,574

3 Claims. (Cl. 213-39) This'invention relates generally to railway rolling stock and is directed particularly to improvements in draft gear mechanism for the same. c

A principal object of the present invention is to provide an improved draft gear for railway cars which is designed to automatically control or eliminate shock incident to the starting and stopping of a train.

Another object of the invention is to provide an 1mproved draft gear construction which automatically controls or takes up slack occurring during the starting or stopping of a train and thereby eliminate the shock which occurs in the use of draft gear of the present known construction.

Still another object of the invention is to provide an improved draft gear construction wherein tension is maintained at all times on the draft springs in both the forward and back movement of the rolling stock.

Other objects and advantages of the invention will become apparent as the description of the same proceeds and the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming a part of the specification, with the understanding, however, that the invention is not to be limited to the exact details of construction shown and described since obvious modifications will occur to a person skilled in the art.

In the drawings:

Figure 1 is a view partly in top plan and partly in horizontal section of the center sills of a railway car showing in position therein the improved draft gear of the present invention, parts of which are broken away.

Figure 2 is a view in side elevation of the draft gear, the center sill on the near side being removed.

Figure 3 is a view in plan of the working parts of the draft gear with the top half of the enclosing housing removed, the coupling bolts between the two halves of the housing being in section.

Figure 4 is a transverse section taken substantially on the line 4-4 of Figure 2.

Figure 5 is a central longitudinal section taken substantially on the line 5-5 of Figure l, the parts being on an enlarged scale.

Figure 6 is a transverse section taken substantially on the line 6 6 of Figure 5.

Figure 7 is a view in plan of the piston bar.

Fig. 8 is a view in perspective of one of the friction blocks utilized in the structure of this invention.

Referring now more particularly to the drawings the draft gear as illustrated in Figure 1 shows the several parts in normal or neutral positionfas they will be when the car carrying the gear is standing and there is neither forward pull nor rearward thrust against the coupler.

In the several views of the drawings the numeral 10 designates the two center sills of the car which extend longitudinally of the frame, not shown, and between the forward and rear ends of which sills the draft gear is supported.

In conventional draft gear construction the center sills have secured to their inner faces, a pair of forward lugs 12 and a pair of rearward lugs 14, these pairs of course being spaced apart lengthwise of the sills to receive a part of the draft gear between them.

The lugs 12, and center sills, have formed therethrough transversely aligned slots 16 to receive the hereinafter described yoke key.

In accordance with the present invention there is pro vided a housing 18 which is of elongate rectangular form 2,706,050 Patented Apr. 12, 1955 ICC and which is of a width and length to position snugly between the center sills 10 and the forward and rearward pairs of lugs 12 and 14 respectively.

The housing 18 is preferably divided longitudinally in a horizontal plane to provide the top and bottom sections a and b and the housing is formed to provide the longitudinal chamber 20, each end wall of which chamber is formed to provide a spring seat socket 22 and opening into these sockets are the longitudinally directed end passages 24.

The numeral 25 generally designates an elongate piston bar, the total length of which is materially greater than the length of the housing 18 as shown in Figure 3. This piston bar, midway of its ends is of square cross section as indicated at 26 while the portions extending from each end of the square section are of circular cross section as indicated at 27.

Extending from opposite sides of the square central section 26 of the piston bar are the outwardly directed wings 28, the forward and rear faces of which are at an acute angle to the length of the adjacent face of the portion 26 so that the front and rear surfaces of each of the wings 28 converge toward the portion 26 forming the sloping friction surfaces 29.

As is clearly shown in Figures l and 3 the piston bar extends centrally through the housing 18, the circular end portions 27 tting snugly for sliding movement in the aligned end openings 24 while the central portion 26 is located within the chamber 20 and the lateral wings 28 are directed toward the opposite sides of the chamber with their outer ends in close proximity to the side walls thereof.

The two halves a and b of the housing 18 are secured together by the corner bolts 30 and the centering of the two halves is effected by the provision of lugs 31 on the under face of the upper half which fit in sockets 32 in the top of the lower half as illustrated.

Within the chamber 20 there are positioned at opposite sides of the central portion 26 of the piston bar, the transversely extending, rectangular friction plates 33, each of which has an opening 34 therethrough for the passage of the adjacent portion 27 of the piston bar.

Upon the outer side of each piston plate is formed the collar 35 through which the adjacent portion 27 of the piston bar passes and encircling this collar and bearing against the friction plate is one end of a heavy spring 36 which encircles the portion 27 of the piston bar and has its other end seated in the adjacent socket 22 as shown in Figure 3. These springs 36 are of equal tension and function to return the parts to the normal centralized or neutral position shown in Figure l when there is no forward pull or rearward thrust upon the draft gear coupler and upon the piston bar.

Each piston plate 33 has formed integral therewith, at each end, the angled friction shoe 37 which provides a sloping friction surface 38 opposing and cooperating, for the purpose hereinafter stated, with the adjacent friction surface 29. There are thus formed forwardly and rearwardly of each of the wing portions 28 of the piston bar the two outwardly converging friction surfaces 29 and 38.

Located between each two opposing friction surfaces' 29 and 38 is a friction block 39 which has a length equal to the height of the chamber 20, as shown in Figure 6.

Each of these friction blocks has the two outwardly convergent faces 40 and 41 which are in sliding contact respectively with the friction surfaces 29 and 38.

The inner side of each friction block 39, by which is meant the side of the block nearest to the central portion 26 of the piston bar, carries two short spring centering pins 42, each of which engages in an end of a laterally directed thrust spring 43, the opposite end of each of which springs 43 engages the adjacent side face of the piston bar portion 26, being preferably seated in a suitable recess or socket 26a in the piston bar portion 26 as shown in Figure 6.

The lateral springs 43 are under constant tension and thus constantly urge the friction blocks 39 outwardly, maintaining them in firm contact with the opposing friction surfaces 29 and 38.

As is clearly illustrated in Figures l, 3 and 5 the piston bar 25 has its ends extending beyond the opposite ends of the housing 18 and the housing is enclosed within the yoke 44. The rear end portion 45 of the yoke 44 engages against the rear end of the piston bar 25 while the forward end of the piston bar is located between the conventional forwardly directed'side wing portions 46 of the yoke, which side wing portions are provided with the slots 47 which align with the transversely aligned slots 16 of the center sills.

The numeral 48 designates the coupler which has the shank portion 49 which is located at its rear end between the wings 46 of the yoke in the usual manner.

The shank 49 of the coupler is provided with the customary transverse slot 50 and extending through this slot is the conventional yoke key 51 which has its ends extending through the yoke slots 47 and through the center sill slots 1 The rear end of the shank 49 of the coupler engages the forward end of the piston bar 25 as shown in Figures l, 2 and 3.

In the normal or neutral position of the draft gear mechanism the friction plates 33 are forced together by the longitudinal springs 36 and the lateral expansion springs 43 will be compressed with the friction blocks disposed inwardly from the side faces of the chamber 20 as shown in Figure l.

Upon the application of a forward pull to the coupler 48 the draft gear 44 will be pulled forwardly, thus shifting the piston bar forwardly. The piston bar wings 28 will thus be forced against the forward friction blocks 39 which will push against the forward piston plate 33 to compress the forward spring 36. At the same time the forward friction blocks 39 will be caused to slide inwardly along the opposed friction surfaces 29 and 3S between which they are located, thus compressing the springs 43.

With the foregoing action the tension upon the rearward spring 36 will be relaxed and the rearward friction blocks 39 will be forced outwardly by the springs 43 in contact therewith, thereby taking up the slack between the rearward friction plate and the wings 28.

[t will thus be seen from the foregoing that when the piston bar is forced forwardly the application of a forward pull to the yoke 44 through the medium of the coupler 48, or upon the reverse operation if the yoke 44 is forced rearwardly by the coupler, any slack occurring between the friction plates 33 and the wings 28 of the piston bar will be taken up by the outwardly or laterally thrust friction blocks 39. Accordingly upon relaxation or reversal of the forward pull or backward thrust which may be applied to the yoke 44 there will be no sudden closing or coming together of separated metal parts to cause a jar or shock such as commonly occurs in the operation of conventional known types of draft gears where upon the application of forward pull or rearward thrust parts of the gear are separated and then come back together with a violent shock or jar when reverse movement is given to the couplers and-the gear connected therewith.

From the foregoing it will be seen that there is provided by the present invention a relatively simple automatic slack controlled draft gear wherein all slack is taken up in such a manner that upon sudden reversal of the movement of the gear parts the slack take up elements shift back smoothly to a normal position to permit various parts of the gear to resume their former positions without shock or jar.

I claim:

l. In railway draft gear including spaced center sills of a car frame, a housing adapted to be mounted between the center sills and having a chamber having forward and rear end openings, an elongate piston bar extending longitudinally through the chamber and projecting at its ends through said openings, a pair of longitudinal springs in the chamber and surrounding the bar, means carried by the bar between the springs which upon movement of the bar lengthwise in one direction will effect compression of one spring and eifect decompression of the other spring, a yoke encircling the housing in the vertical plane of the piston bar and having constant operative connection at its ends with the ends of the bar, and laterally shiftable spring actuated means in the housing chamber for taking up slack between the decompressed spring and said means carried by the bar upon compression of said one spring.

2. The invention according to claim 1, wherein said laterally shiftable means comprises friction blocks disposed upon opposite sides of the piston bar, and said means carried by the bar comprises members xed to the bar and other members slidable on the bar with said friction blocks interposed between the fixed and slidable members.

3. In railway draft gear including spaced center sills of a car frame, an elongate housing lixed against movement between the sills and having a chamber having forward and rear end openings, an elongate piston bar extending longitudinally through the chamber and projecting at its ends through the openings beyond the ends of the housing, a draft yoke enclosing the housing and having constant connection at its ends with the ends of the rod, oppositely directed ears carried by said rod within the chamber, transverse plates in the chamber at opposite sides of said ears and being adapted for movement independently of the rod a coil traction spring interposed between each of said transverse plates and the adjacent end of the chamber, friction blocks interposed between said ears and the adjacent plates, said blocks and the ears and plates engaged therewith having outwardly converging bearing faces, and spring elements between the blocks and the piston bar.

No references cited. 

